phase porting????
 

Ok this one is for all you preformance guys , a few guys at the field were tallking and phase porting there 2 strokes to get more out of them . How is this done and what are the benifits? I race pylon and the same plane weighing the same as mine and the same prop the same engine is pulling right past me on the straigts like I'm running a .25 and they have a .40 > BTW My .40 is a hot .40 fx and it's stock theres is not .Please some kind of info will help . DS

RE: phase porting????
 

I did a Google search on "phase porting of 2-stroke engines" came up with nothing directly quoted. You might try a pylon racing website.

CR

Er, since "phase porting" didn't come up on Google, you might consider that those guys were messin' with your head.

RE: phase porting????
 

You mean change timing of porting in the 2 stroke engine?

Google "Two stroke porting" or "two stroke timing"..;)

RE: phase porting????
 

Quote:

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ORIGINAL: streetrodder

... My .40 is a hot OS.40FX...

---

DS,


This clause in an oxymoron...

There is no such thing as a 'hot OS.40FX'...

It is just an average power sport engine.


Also, because it has an ABN piston-and-liner set, you cannot successfully port it...
The electro-less nickel coating relies on surface continuity, for its integrity.

If you Dremel the ports, this continuity will be broken and the mediocre bond-strength of the nickel to the brass, will allow the nickel to peel off...


If you do think porting the sleeve is within your scope of possibilities, start with a true-chromium P+L set, such as the one for a Magnum/ASP .40 Pro (made by Sanye in China).

The chromium has a superior bond strength to the brass and will not peel off.

RE: phase porting????
 

Or they could have been saying port phazing which probably refers to raising the port (or lowering it) to change the intake and exhaust timing. We generally refer to the intake and exhaust as "events" , compression ,exhaust,intake,power are events but in a 2 stroke they are more blurred and overlap more. Raising or lowering the liner in the engine changes the timing of these events.

RE: phase porting????
 

Or they could be talking about one I. port opening before the others...such as the boost port opening before or after the main ports? (staggered timings )

RE: phase porting????
 

I don't know about phase porting, but some of the stuff done in the thread below makes sense from my automotive knowledge. . . .

http://www.e-maxximumrc.com/html/nitro_motor_mod.html

Jack

RE: phase porting????
 

I think that this whole thing comes down to a tuned exhaust.
By playing around with the exhaust and changing the phase of the exhaust wave you can do two things...
One reduce the back pressure of the exhaust allowing the hot gas out of the engine.
Two by changing the phase of the reflected wave scavenge more exhaust out of the cylinder allowing more fresh charge into the engine.
Save yourself a lot of hassle and buy a Jett muffler, it will boost the performance of your engine.
Another thing you can do is try a tuned pipe type of exhaust like those the control line stunt guys use.
As far as porting you engine itself it's a lot of work and you need special equipment, and you will have to strip the nickle and re-apply it to the entire engine.

Now on a positive note you can gain a lot just by using a better exhaust setup on the stock motor.
Also you can play around with the prop and anything on the plane that can or will produce drag, such as sealing the control surface gaps, or fairings on the control linkages.
Using the right spinner/prop combo as well as wheel pants and thinner wheels also can help you squeeze out some more performance, without buying a $350, engine as well.

RE: phase porting????
 

If you want to tune a engine with tuned pipe, use this program http://www.mh-aerotools.de/airfoils/javapipe_en.htm and select a tuned pipe in right size later after the parametre are calculated.

RE: phase porting????
 

Some areas I touched upon but did not really address...
A lot of the speed that can obtain is effected by many issues.
One of the most important of these is the weight, and the COG.
If your plane is heavier it will not fly as fast as the others.
If your COG is set up different and you have to use more elevator trim this will slow you down as well.
Everyone thinks that more power is the only way to get ore speed out of an airplane, while that is true to a point, it is not the only factor involved.
Sometimes something as having you high end a bit rich on the ground will buy you some more rpm's in the air.
If you have wire gear rather than a flat metal or composite type this will be more draggy.
A big spinner rather than a prop nit will give you better penertration.
The same plane with a few different items will perform much better with out all the fancy stuff you can do to the motor.
Look through the speed plane forum and pylon you will get some ideas.
I have found that sometimes something as simple as cutting down the unused portion of my control horns will give me a couple more knots of airspeed.
So look over your airplane carefully and see just what may be slowing you down.
The first thing I would look for is added weight, and were the COG is set, that along with the other things I mentioned in the prior post.

RE: phase porting????
 

They recommend polishing the outside of the crank, but recommend puting a sharp fang in the counter weight to create turbulance? Seems to me if polishing it is a good idea then the fang is a bad idea, or vicea versa.

RE: phase porting????
 

Thanks for the info guy alot of good point I might have over looked cg gaps to much throw all things I didn't take into concideration. Well I lost my plane in a midair so the next one will be looked at very closely.

RE: phase porting????
 

You would be surprised how much "tricks" can boost you top speed...
Not to mention it's fun seeing the other guys trying to figure out what you did...
When you get better performance out of an given airframe.

RE: phase porting????
 

Dar, I can't agree with that blanket statement(red).
Myself and others have successfully ported ABN liners, but it is risky for all the reasons you gave. I have raised the exhaust port (and other improvements) )on a OS 55 AX and that was several years and many gallons ago.

A sharp (fresh) diamond burr and diamond jewelers files are the tools of choice. Knowledge of filing direction and how to break the edge of the of the nickel plating may increase the chances of success.

To those that are contemplating porting to the liner AND crank. If you don't know EXACTLY why and what you are doing, chances are that even small changes will do more harm than good, everything is a balancing act. The nickel plating lowers your odds even more. If you are willing to accept this, go for it.

RE: phase porting????
 

Quote:

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ORIGINAL: freakingfast

Myself and others have successfully ported ABN liners, but it is risky for all the reasons you gave.

---

Karl,


As I wrote (and you agreed), it is rather risky...

The Magnum/ASP .40 Pro P+L set is a drop-in replacement in the OS.40FX crankcase and on the con-rod and wrist-pin.


Why take the chance that the original OS sleeve will peel, if you can start with the much cheaper Chinese set and be quite sure it never will?

With its lower cost set, if you 'miss' with the grinder while porting, it will not hurt you as much as well...[8D]

RE: phase porting????
 

Why does everyone think the liner openings need opened up? Ihave seen a lot of improvement from just porting the inside of the case and smoothing up the intake port. It really is super easy, just takes some concentration.

RE: phase porting????
 

I have quite a bit of experience running .12-.15 size Mod car engine's, and these mods do work if you know what you are doing.;) All you have to do, is to look inside any of the purchased Mod Car engines that come with these mods to begin with to realize it really does work.
Another simple trick is to bevel the bottom of the liner, since most of the stock engines I have had apart do not have much of a Bevel.;)
I have never tried Modding plane engines with any of the extreme Mods, because I do not think they spin high enough rpm to make it pay off where the .12-.15 size Mod engines are easily spinning upward of 35,000 and more rpm.;)

RE: phase porting????
 

Funny that you should mention that.
I started out just wanting to give the engine a little boost, so I radiused the intake opening in the crankshaft. The area where they cut a flat, the entire sharp edged perimeter was radiused but not where it where to the O.D of the crank as to change timing or promote leakage. The lower out side edge of the boost and transfer ports were radiused, keeping with the rear wall aim in mind. The outside diameter of the fuel inlet in the carb's throat was air streamed also.

When I ran it, it exhibited symptoms of an engine with too much compression. Apparently it was stuffing more mixture on top of the piston. I went to FAI fuel.... low and behold, it pulled the same prop better than it did stock on 15%. The problem is I had so much 15% fuel on hand, so instead of shimming the head, I raised the exhaust port with two notches on each side of the window's center post. This helped lower the compression and gave me extra boost on the pipe. I cant remember how much it was raised, I think it was 180 degrees. Had to increase my Idle speed a bit, but I gained 800 rpm with the same prop and lost some fuel economy.

Everything is a balance, give and take. Worth it? Naw, just get a bigger engine.

RE: phase porting????
 

This is exactly what I do to all my engines. I do all the work on the outside of the sleeve and have done OS nickel liners too there`s no risk at all of peeling due to this kind of work. I measured the improvements in all my aero engines and the Tower 75 immediately rewarded me with another 600 rpm, my MVVS 49 gave 500 rpm more, which seems to be about what the rest of my engines also increased by doing this. I have done buggy engines too, and lately I`m hooked on speed nitro boats . I have flow ported and polished my Dynamite .32 marine engine and fitted a bigger carb and a different pipe and now my Thunder Cat 31 flies (It actually gets airborne due to high speed alone)

I`m sure altering the timing will give even more power, but I`m very pleased with my results for this rather quick and easy and almost risk free mods

RE: phase porting????
 

Do you think to polish the crankshaft intake corridor will be useful?

RE: phase porting????
 

I don`t know, I have never done that myself. Some say that a mirror finish in the intake is not so good because the mixture is best atomised and blended if there`s small imperfections that cause turbulence that aids in the atomising of the fuel and air.

buggy engine modders often add epoxy in the intake corridor just below the carb to give a smooth turn for the mixture instead of it smashing straight down and loosing velocity. They try to make it a u-turn instead of aan almost 90 degree turn if you know what I mean. This mod is factory standard in higher end buggy engines.

I have also ground turbo cut in the crank of my ASP XLS 52, but didn`t tach it before and after, so I really don`t know if it had any positive effekt. I own several buggy engines and when I mod my aero and marine engines I try to copy some of what is factory standard in my Sirio buggy engines and then even add some more mods:D.

RE: phase porting????
 

Thks.Asmund.

RE: phase porting????
 

While many of the mods make sense to me, I don't understand the bevelling the bottom of a liner.

I assume you are bevelling the outside, so that that air splits and flows easier up the ports???

Thanks,

Jack

RE: phase porting????
 

Jack. yes